Q. I am a brand new user of a Linux iptables and I can’t find how to instruct my iptables to delete or unblock an IP address listed in iptables firewall. I’m using Debian Linux version. Can you help please?

Q. How do I display / list all rules in the selected chain? How do I find out which rules are active? What is blocked and opened with my firewall?

A. To List all rules in the selected chain use the -L option. If no chain is selected, all chains are listed. As every other iptables command, it applies to the specified table. The -n option help to print IP addresses and port numbers in numeric format.

The –line-numbers option adds line numbers to the beginning of each rule, corresponding to that rule’s position in the chain. The -v option makes the list command show the interface name, the rule options (if any), and the TOS masks. The packet and byte counters are also listed, with the suffix K, M or G for 1000, 1,000,000 and 1,000,000,000 multipliers respectively (but see the -x flag to change this).# iptables -L -v -n --line-numbers